Coiled-coil mediated heterodimerization functional interaction trap

Abstract

Fusion proteins containing coiled-coil heterodimerization domains substituted for modular protein binding domains useful for validating functionally relevant protein-protein interactions, directing enzymes to specific substrates, and screening fusion libraries for functionally important interaction partners.

What is claimed:  
     
       1. An assay for determining the activity of a protein—protein interaction comprising a) transforming a cell with a first vector containing a gene encoding a fusion protein comprising a protein containing a modular protein binding domain MPBD and an exogenously introduced a first coiled-coil dimerization which comprises a WIN-ZIP-A1 synthetic amphipathic helix and with a second vector containing a gene encoding a second fusion protein comprising a binding site for the MPBD and an exogenously introduced second coiled-coil dimerization domain interactive with the first dimerization domain, which comprises a WIN-ZIP-B1 synthetic amphipathic helix, b) culturing the transformed cell, c) comparing the activity to a base line control, d) detecting and measuring changes in activity for determining th activity of the protein—protein interaction, wherein the MPBD domain consists of src homology 3 (SH 3 ) and wherein the protein containing the modular protein binding domain (MPBD), which contains a WIN-ZIP-A1 helix is a tyrosine kinase. 
     
     
       2. The assay of  claim 1  wherein the base line control constitutes at least two cells wherein each of said cells is transformed by one of the two vectors and not the other.